SCIENCE 1206 UNIT 1 CHEMISTRY
UNIT OUTLINE CHEMISTRY TERMINOLOGY BOHR DIAGRAMS ATOMS versus IONS NAMING COMPOUNDS IONIC, MOLECULAR, ACIDS CHEMICAL REACTIONS BALANCING CHEMICAL EQUATIONS 5 TYPES of REACTIONS
IMPORTANT TO KNOW... You will get a PERIODIC TABLE!!! It is your best friend for this unit! You will need it each and every day. Take care of it, cherish it, appreciate it!
CHEMISTRY TERMINOLOGY Matter: Anything that has mass and volume (takes up space). What is not matter? Energy Mass: The amount of matter an object contains, measured in grams, g.
3 STATES OF MATTER 1. SOLID Definite volume and shape 2. LIQUID Definite volume, indefinite shape 3. GAS Indefinite volume, indefinite shape Chemistry Subscripts (s) - solid (l) - liquid (g) - gas (aq) - aqueous (dissolved in water)
WHAT IS CHEMISTRY? Chemistry is the study of the properties and chemical changes/reactions of matter. Examples of chemical reactions: Rusting Burning/Combustion
Physical Property - quality or characteristic of a substance that can be observed WITHOUT a chemical reaction. Examples: State of matter Hardness Colour Malleability Ductility Odor Solubility Brittleness Conductivity Melting and Boiling Points
Physical change - a change in state of matter of a substance. Examples: Melting/fusion (s l) Freezing (l s) Evaporation (l g) Condensation (g l) Sublimation (s g) Deposition (g s)
Chemical property - a behavior of a substance that can only be observed when a chemical change is taking place. Example: Magnesium ribbon burning 2 Mg (s) + O 2(g) 2 MgO (s) + light energy The chemical property is that light is given off when magnesium is burned. Chemical change - a change in which one or more new substances is formed. They are difficult to reverse. Example: Iron Rusting 4 Fe (s) + 3 O 2(g) 2 Fe 2 O 3(s)
Here are some chemical change indicators: COLOUR CHANGE
BUBBLES OF GAS
SOLID (PRECIPITATE) FORMATION
HEAT/LIGHT GIVEN OFF
Chemists can use various tests to determine the presence of certain gases and other substances: 1. Oxygen gas is present if a glowing splint burst into flame.
2. Hydrogen gas is present if a lit splint causes a pop. 3. Carbon dioxide is present if limewater solution turns milky when the gas is bubbled into it.
4. Water vapor is present if cobalt chloride test paper changes from blue to pink. 5. Acid is present if litmus paper turns red.
6. Base is present if litmus paper turns blue. 7. There is an aqueous solution of salt if it conducts electricity.
Reactants - starting Materials in a chemical reaction Products - new substances formed in a chemical reaction Chemical Reaction - reactants go to form products. Example: C (s) + O 2(g) CO 2(g)
Pure substances - made up of only one type of atom or atom combination. There are 2 Types of Pure Substances: 1. Element CANNOT be broken down into a simpler substance by a chemical change. Made up of 1 type of atom. Element symbols are always written with the first letter UPPERCASE and the second letter LOWERCASE. Element NAMES are always written in LOWERCASE letters. Examples: Na - sodium Li - lithium Ar - argon W - tungsten
2. Compound CAN be broken down into its elements with a chemical change.. Made up of two or more different elements are chemically joined together in fixed proportions. Examples: NaCl C 12 H 22 O 11 CH 4 H 2 O
Counting Atoms 1. The symbol of an element represents one atom of that element. Eg. Ba= 1 atom of barium Hg= CO= 1 atom of carbon 1 atom of oxygen 2 atoms in total NaI= 2. A subscript is a number written at the lower right hand corner behind the symbol of an element. If there is more than one atom of the same element, then a subscript number is used. Eg. Cl 2 = 2 atoms S 4 = H 2 O 3 = 2 atoms of hydrogen K 2 CO 3 = 3 atoms of oxygen 5 atoms in total If you don t see a number assume there is 1 atom!!
3. A subscript outside a bracket multiplies all the elements inside the bracket ONLY! Eg. Ca 3 (PO 4 ) 2 = 3 atoms of calcium 2 atoms of phosphorous 8 atoms of oxygen 13 atoms in total Pb(NO 3 ) 2 =
4. A coefficient is a number written in front of a chemical name and it indicates the number of elements or molecules present. (if 2 double everything, if 7 multiply every atom by 7 in that molecule) 9C= 9 atoms of carbon gas 4O 2 = 3NaSO 4 = 3 formula units of NaSO 4 5ZnPO 4 = 3 atoms of sodium 3 atoms of sulfur 12 atoms of oxygen 21 atoms in total How to Count Atoms - worksheet
Diatomic Molecules There are 7 elements that are diatomic, or found in pairs, in their natural state. These are: H 2, O 2, F 2, Br 2, I 2, N 2, Cl 2, Also P 4 and S 8 Memory tool: P S H O F Br I N Cl